JPH059463B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD This invention relates to improved polyester compositions. Specifically, a linear polyester containing a polyolefin or a copolymer thereof and a higher fatty acid amide or a metal salt of a higher fatty acid amide and a higher aliphatic monocarboxylic acid and capable of producing a film with excellent flatness, lubricity, and electrical properties. The present invention relates to a composition.

[Prior art and its problems]

In recent years, polyethylene terephthalate film has made remarkable progress in the fields of magnetic tape, photography, capacitors, packaging, and microfilm. However, in the case of polyester films, if the surface is not slippery, adhesion occurs between the films, which not only reduces work efficiency during film formation or post-processing, but also reduces the product value due to poor winding appearance. This will cause problems such as a significant drop in the performance.

On the other hand, when used as a magnetic recording medium such as a magnetic tape, one of the most important properties is that the surface has little unevenness, that is, it is excellent in so-called flatness, and it is also required to have excellent lubricity.

In addition, improved lubricity and electrical properties are important for plastic and capacitor applications.
A number of techniques have been proposed and implemented to improve these problems, but they can be broadly divided into (1) technologies that are inert to the polyester synthesis reaction system, such as titanium dioxide, talc, kaolinite, calcium carbonate, and silicon oxide; method of adding fine particles. (hereinafter referred to as the inert particle addition method) (2) There is a method in which part or all of the catalyst, color inhibitor, etc. used during polyester synthesis is precipitated during the reaction process and exists as fine particles (hereinafter referred to as the internal particle generation method). .

However, the method of adding inert particles has the following drawbacks when attempting to impart sufficient lubricity and flatness.

In other words, in the case of fine particles such as titanium dioxide and dry silica, lubricity cannot be obtained unless they are added in large amounts, and if added in large amounts, transparency may be impaired or coarse protrusions may develop due to secondary agglomeration of particles. death,
Flatness cannot be obtained.

In addition, in the case of talc, kaolin, etc., since these are particles obtained by crushing and classifying natural minerals, adding the amount necessary to obtain lubricity will increase the proportion of coarse particles, the roughness of the average particle size, and the agglomeration. etc., it is difficult to obtain good flatness.

On the other hand, in the internal particle generation method, the disadvantages of the inert particle addition method are improved to some extent. Examples of using a metal compound such as calcium or lithium as an internal particle generation method are already known, and the resulting particles have a relatively small diameter and have sufficient affinity for polyester.

However, in the case of the internal particles generated here, there are still many coarse particles mixed in, probably due to the strong cohesive force between the particles, and these coarse particles not only deteriorate the flatness of the film but also cause problems during melt forming. This may cause filter clogging and film tearing.

Furthermore, Japanese Patent Publication No. 34-5144 states that when a trivalent phosphorus compound is used in combination, the alkaline earth metal salt particles of terephthalic acid actually decrease. This is due to the fact that the internal particles produced by the addition of the phosphorus compound become finer. For this reason, the obtained film has excellent transparency and flatness, but has the problem of insufficient slip properties and blocks during the winding process.

As described above, the internal particle generation method has the disadvantage that the amount and diameter of the particles produced are likely to change and it is difficult to control the slipperiness.

[Purpose of the invention]

The object of the present invention is to provide a linear polyester composition capable of producing a film having lubricity, flatness, and electrical properties that could not be achieved using the conventional techniques.

[Structure of the invention]

The object of the present invention described above is to: (A) 0.1 to 10 parts of polyolefin or its copolymer to 100 parts by weight of polyester whose main repeating unit is ethylene terephthalate;
Parts by weight and (B) Higher fatty acid amide having 18 to 33 carbon atoms
0.005 to 2 parts by weight, or 0.005 to 2 parts by weight of the higher fatty acid amide and at least one metal salt compound or partial metal salt compound of a compound consisting of a higher aliphatic monocarboxylic acid having 18 to 33 carbon atoms.
This is a polyester composition containing 2 parts by weight.

The polyester composition of the present invention is characterized by containing a polyolefin or a copolymer thereof and specific amounts of a specific higher fatty acid amide or a metal salt of a higher fatty acid amide and a higher aliphatic monocarboxylic acid, each of which is a single component. The purpose of this invention is to improve the smoothness, flatness, and secondary processability of polyester molded products, especially polyester films, which could never be obtained by conventional methods.

Next, the present invention will be explained in detail. The polyester in the present invention is mainly composed of polyethylene terephthalate, which can be molded into fibers, films, and other molded products, and can be formed by various conventional methods. It is manufactured by Of course, these polyesters may be homopolyesters or copolyesters, and copolymerizable components include, for example, diethylene glycol,
Diol components such as propylene glycol, neopentyl glycol, polyalkylene glycol, p-xylylene glycol, 1,4-cyclohexanedimethanol, 5-sodium sulforesorcin, adipic acid, sebacic acid, phthalic acid, isophthalic acid, 2,6 - naphthalene dicarboxylic acid,
Examples include dicarboxylic acid components such as 5-sodium isophthalic acid, multitubular dicarboxylic acid components such as trimellitic acid and pyromellitic acid, and oxycarboxylic acid components such as p-oxyethoxybenzoic acid.

When the dicarboxylic acid component is a dicarboxylic acid, after an esterification reaction with a glycol, and when a dicarboxylic acid ester is used, after an esterification reaction with a glycol, the resulting prepolymer is polycondensed at high temperature and reduced pressure to obtain a polyester. It is also possible to polycondensate using the prepolymer itself as a starting material.

In the present invention, polyolefins include polyethylene, polypropylene, poly-4-methylpentene-1, isotactic polybutene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ionomer ethylene-propylene copolymer, etc. Refers to a copolymer mainly composed of α-olefins or copolymers of α-olefins.

If the amount of polyolefin or its copolymer is less than 0.1 part by weight, the molded product will not have good slipperiness, and
If it exceeds 10 parts by weight, the mechanical and thermal properties of the polyester will deteriorate, and the strength of vapor deposition when aluminum metal etc. is vapor-deposited will decrease, resulting in poor secondary processability.

The higher fatty acid compound contained in the polyester of the present invention is a metal salt compound or a partial metal salt compound of a compound consisting of a higher aliphatic monocarboxylic acid having 18 to 33 carbon atoms as a main component, and specific examples include stearic acid and nonadecanoic acid. , arachic acid, carnaubic acid, lignoceric acid, cerotic acid, montanic acid, petroselic acid, oleic acid, erucic acid,
Examples include linoleic acid and acid mixtures containing these, and metal species include alkali and/or alkaline earth metals such as lithium, sodium,
Potassium, barium, magnesium, calcium, and strontium are mentioned, and particularly preferred compounds include magnesium stearate, calcium montanate, sodium montanate, calcium montanate, and sodium erucate.

Furthermore, those obtained by partially esterifying a higher fatty acid with a dihydric alcohol having 2 to 4 carbons in the alkylene group and then neutralizing it with the above-mentioned metal oxides or hydroxides are also available. It can be used preferably.

Further, specific examples of the higher fatty acid amide having 18 to 33 carbon atoms of the present invention include stearic acid amide, oleic acid amide, erucic acid amide, behenic acid amide, montanic acid amide, etc., and mixtures containing these as main components. In addition, other substituted fatty acid amides include the general formula [In the formula, R ₁ is an alkyl, alkenyl or cycloalkenyl group, R ₂ is H or an alkyl group,
R ₃ may contain an alkyl group, and R ₁ and R ₃ may contain an oxy group or an alkoxy group. However, the total number of carbon atoms is 18 to 33. ] You may use the compound shown by these.

Specific examples include acetic acid-N-stearylamide,
Examples include propionic acid-N-methyl-N-stearylamide.

The effects of these higher fatty acid metal salts and/or higher fatty acid amide compounds can be obtained by the presence of polyolefins or copolymers thereof.
The surface of molded products such as fibers is extremely smooth even though it is flat.

However, if the number of carbon atoms in the fatty acid compound is less than 18 or if the amount added exceeds 2 parts by weight, bleed-out to the surface of the molded product will be severe and the secondary processability will be poor, and if the number of carbon atoms exceeds 33, Cannot obtain smoothness.

Furthermore, if the amount added is less than 0.005 parts by weight, the flatness and slipperiness of the present invention will hardly be obtained. A particularly preferable addition amount range is 0.01 to 1.0 parts by weight, more preferably 0.05 to 0.5 parts by weight.

The polyolefin and higher fatty acid compound may be added to the polyester before the polyester polymerization reaction, during the polymerization reaction, or after the polymerization reaction is completed, or may be added during melt extrusion molding.

The composition of the present invention can be obtained by separately producing polyethylene terephthalate containing polyolefin and higher fatty acid compound and kneading them in a melt molding process, or by producing polyethylene terephthalate containing a large amount of polyolefin and/or higher fatty acid compound. A method of dilution is also preferably employed.

In addition, within the scope of the invention, the polyester composition of the present invention includes fine particles, i.e., internal particles, in which part or all of the catalyst, color inhibitor, etc. used during polyester synthesis are precipitated during the reaction process, and/or carbon dioxide. Silicon, calcium carbonate, aluminum silicate, barium sulfate, calcium phosphate, talc, titanium dioxide,
Inert particles such as calcium terephthalate and calcium silicate can be used in combination. Further, it is also possible to appropriately select the use in combination with pigments, dyes, antistatic agents, weatherproofing agents, and the like.

The film composition of the present invention may be formed into an unstretched film, a uniaxially stretched film, or a biaxially stretched film, and particularly a biaxially stretched film exhibits remarkable effects.

To produce a biaxially stretched film, for example, a sheet-like product obtained by melt-extruding the composition is heated at 70 to 140°C in the longitudinal direction.
After stretching 2.5 times to 5.5 times at a temperature of
Obtained by biaxial stretching by stretching 4.5 times.

〔Effect of the invention〕

The polyester composition of the present invention has the following excellent effects by containing a specific polyolefin and a specific amount of a higher fatty acid amide or a higher fatty acid amide and a metal salt of a higher aliphatic monocarboxylic acid. be done.

(1) Since the film surface has excellent flatness, it is extremely useful, especially in magnetic tape applications, as it has few drawbacks such as dropouts and skipping during playback.

(2) Good electrical characteristics.

(3) Excellent processability and handling due to good friction properties.

(4) There is less clogging of the filter and less tearing of the film during the film melt forming process.

As described above, the polyester composition of the present invention can be used for fibers, unstretched films, stretched films, and plastics, and is particularly suitable as a composition for biaxially stretched films.

The present invention will be explained in detail with reference to Examples below.

In addition, each characteristic value of the polyester in the Examples was measured by the following method.

A. Aluminum metal vapor deposition strength A polyester adhesive tape was attached to the metal vapor deposited surface, and the state when it was peeled off was shown using the following 5-step method.

1: Al is completely peeled off to the adhesive tape side without resistance.

2: More than 50% of the area is peeled off to the adhesive tape side.

3: 10-50% of the area is peeled off to the adhesive tape side.

4: The portion peeled off to the adhesive tape side is 10% or less.

5: Not peeled off to the adhesive tape side.

A rating of 3 or higher shown in the above ranking is a practically preferable level.

B Film haze Measured according to ASTM-D1003-52.

C Friction coefficient Using a slip tester manufactured by Toyo Tester
Measured according to ASTM-D-1894B method. Note that the coefficient of static friction was used as a measure of the slipperiness of the film.

D Film surface roughness The film surface was observed using a stylus roughness meter, and the maximum roughness and average roughness (μ) were determined.

E Dielectric breakdown voltage Measured according to JIS-C-2318 using an AC withstand voltage tester.

Comparative Example 1 100 parts by weight of dimethyl terephthalate, 70 parts by weight of ethylene glycol, 0.05 parts by weight of calcium acetate as a transesterification catalyst, and 0.03 parts by weight of antimony trioxide as a polymerization catalyst were added, and a theoretical amount of methanol was distilled between 140 and 230°C. The transesterification reaction was completed. Then add trimethyl phosphate to the system.
0.043 parts by weight was added. Next, the pressure in the system was gradually reduced to 285°C under a reduced pressure of 1 mmHg to distill off ethylene glycol. When the intrinsic viscosity of polyethylene terephthalate reached 0.62, low density polyethylene ("Sumikasen") was added to 100 parts by weight of the polyester. -L705'', MI=7.0) and 0.2 parts by weight of sodium montanate were added and stirred and kneaded at 285°C under reduced pressure for 20 minutes. The composition thus obtained was discharged from a polycondensation reactor and formed into chips.

After drying the polymer chips, they were melt-extruded using a 90 mmφ extruder to obtain an unstretched sheet.
The film was biaxially stretched at a longitudinal stretch ratio of 3.2 times and a transverse stretch ratio of 3.4 times according to a conventional method, and then heat treated at 200°C to obtain a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm. The static friction coefficient of the obtained film was 0.51, the average roughness of the film surface was ±0.014, and the maximum roughness was ±0.18μ.
Both flatness and slip properties were good. Further, the dielectric breakdown voltage was 460V/μ.

In addition, when aluminum was vapor-deposited on the film surface and the adhesion of the vapor-deposited film was examined, the adhesion rank was 3.
It was hot.

Comparative Example 2 Polyester 100 was prepared in the same manner as in Comparative Example 1.
Although 1.0 parts by weight of low-density polyethylene was added to each part by weight, the biaxially stretched film had good flatness, but had a static friction coefficient of 1.10 and no lubricity at all.

Comparative Example 3 Polyester 100 was prepared in the same manner as Comparative Example 1.
As for the properties of the biaxially stretched film obtained by adding only 0.2 parts by weight of sodium montanate to the weight part, the flatness was good as in Comparative Example 1, but the coefficient of static friction was 0.98, and the lubricity was poor.

Example 1 A transesterification reaction was carried out in a conventional manner by contacting 100 parts by weight of dimethyl terephthalate and 62 parts by weight of ethylene glycol with 0.09 parts by weight of calcium acetate, and the resulting product contained 0.03 parts by weight of antimony trioxide, 0.08 parts by weight of dimethyl phenylphosphonate, and 0.04 parts by weight of phosphorous acid were added. Finally, polycondensation was carried out at 280°C under reduced pressure according to a conventional method, and 0.3 parts by weight of polypropylene (Mitsui Noblen FO-100 manufactured by Mitsui Toatsu Co., Ltd., MI = 1.0) was added in the same manner as in Example 1. , polyethylene terephthalate chips containing 0.05 parts by weight of erucic acid amide were obtained.

Using the chip, in the same manner as in Comparative Example 1.
A 6μ biaxially stretched film was obtained.

The obtained film had a coefficient of static friction of 0.63, an average film surface roughness of 0.010μ, a maximum film surface roughness of 0.15μ, and both flatness and slipperiness were good.The dielectric breakdown voltage of the film was 500V/μ. It was hot.

Comparative Example 4 In the same manner as in Example 1, calcium carbonate with an average particle size of 2.5 μm was added instead of polypropylene and erucic acid amide, but the dielectric breakdown voltage was low even though the static friction coefficient of the biaxially stretched film was 0.64. was inferior at 420V/μ.

Example 2 Polypropylene (“Mitsui Noblen FO-100” manufactured by Mitsui Toatsu Co., Ltd., MI = 1.0) was prepared in the same manner as in Example 1.
Polyethylene terephthalate chips containing 0.3 parts by weight, 0.05 parts by weight of montanic acid amide, and 0.2 parts by weight of magnesium stearate were obtained.

Using the chip, in the same manner as in Comparative Example 1.
A biaxially stretched film of 6 μm was obtained.

The obtained film had a static friction coefficient of 0.62, an average film surface roughness of 0.009μ, a maximum film surface roughness of 0.14μ, and had good flatness and slipperiness.The dielectric breakdown voltage of the film was 510V/μ. .

Claims (1)

[Scope of Claims] 1. (A) 0.1 to 10 parts by weight of polyolefin or its copolymer based on 100 parts by weight of polyester whose main repeating unit is ethylene terephthalate.
Parts by weight and (B) Higher fatty acid amide having 18 to 33 carbon atoms
0.005 to 2 parts by weight or 0.005 to 2 parts by weight of at least one metal salt compound or partial metal salt compound of a compound consisting of 0.005 to 2 parts by weight of the higher fatty acid amide and a higher aliphatic monocarboxylic acid having 18 to 33 carbon atoms.
-2 parts by weight of a polyester composition.